How elevation model is calculated in GISGRO?
All starts with a Digital Elevation Model (DEM). A DEM is a raster, i.e. a grid of squares, where each grid cell has a height value.
First, we formulate a grid, in which the size of a cell is determined by the extent of the dataset. The longest side of dataset’s bounding box determines the used cell size for the digital elevation model.
You can also upload gridded dataset; in this case we use the predefined grid for calculation.
To define which points of a point cloud belong to a certain grid cell, we take one point in the middle of the cell and use it as a center point of a circle. The height values of the points in this circle are used in calculating the mean height. We use inverse distance to a power with nearest neighbor searching method with power factor of 2, meaning that the points closer to the middle have more weight in calculations. All points within the search radius are included in the calculations.
We calculate simultaneously mean and shallowest digital elevation models, so you can choose between the two options in visualizing or doing calculations on the elevation models. The digital elevation model with shallowest elevation values for each cell is commonly used as a shoal biased bathymetric chart.
Contact support@gisgro.com if you want more information.
First, we formulate a grid, in which the size of a cell is determined by the extent of the dataset. The longest side of dataset’s bounding box determines the used cell size for the digital elevation model.
You can also upload gridded dataset; in this case we use the predefined grid for calculation.
To define which points of a point cloud belong to a certain grid cell, we take one point in the middle of the cell and use it as a center point of a circle. The height values of the points in this circle are used in calculating the mean height. We use inverse distance to a power with nearest neighbor searching method with power factor of 2, meaning that the points closer to the middle have more weight in calculations. All points within the search radius are included in the calculations.
We calculate simultaneously mean and shallowest digital elevation models, so you can choose between the two options in visualizing or doing calculations on the elevation models. The digital elevation model with shallowest elevation values for each cell is commonly used as a shoal biased bathymetric chart.
Contact support@gisgro.com if you want more information.
Updated on: 24/01/2025
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